The radical transformations that occurred within the Movement of Arab Nationalists (MAN) during the revolutionary decade of the 1960s resulted in one of the most significant ideological shifts in contemporary Arab history. From as early as 1960, figures within MAN including Nayef Hawatmeh, Muhsin Ibrahim, and Abdel Fattah Ismail grew increasingly critical of the limits to Arab nationalism as they begun challenging the leadership over the role of revolutionary armed struggle in the Arabian Peninsula and the absence of any class analysis in the movement. These frustrations were demonstrated in MAN’s willingness to collaborate with Arab bourgeois nationalists and regimes who were viewed by the radical generation of MAN as complicit in the loss of Palestine in 1948. This paper examines the social, historical, and political conditions that shaped the dissolution of the MAN and the subsequent rise of revolutionary Marxist organizations from Palestine to Aden, arguing that these processes constituted a radical reconfiguration, rather than a suspension, of transnational bonds of solidarity tying the Arabian Gulf and Peninsula to the liberation of Palestine. These bonds were now conceptualized anew. Rather than being viewed as struggles primarily connected through common national belonging, the struggles of Palestine and the Arabian Peninsula were now situated as part of an anti-colonial and anti-capitalist struggle in the Global South. How did this new conceptualization emerge? Utilizing primary sources published by these movements along with Arabic memoirs, this paper will answer this question by revisiting significant 1960s ideological milestones. It will specifically focus on the clash between the conservative leadership of the MAN and its radical cadres who questioned the efficacy of the anti-colonial nationalist regimes in Egypt, Iraq, and Syria. Whereas most accounts of Arab intellectual history focus on the Arab defeat of 1967 (Naksa) as the key ideological turning point of the decade, this paper argues that the defeat of Arab armies in that year expedited, rather than initiated, a trend that had started much earlier. This intellectual current culminated in the formation and rise of radical liberation struggles out of local MAN branches in the Arabian Gulf and the Palestinian refugee camps throughout the revolutionary decade of the 1960s. As this paper will show, throughout these ideological clashes, the MAN’s successor organizations shifted away from nationalist towards Marxist politics as they fought to internationalize their struggles against colonialism and imperialism.